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Comparative quality of pasturage on Western Canadian ranges 1947

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COMPARATIVE QUALITY Of PASTURAGE ON WESTERN CANADIAN RANGES by Thomas G. W i l l i s Thesis submitted i n P a r t i a l F u l f i l m e n t of the Requirements f o r the Degree of MASTER OF SCIENCE IN AGRICULTURE i n the Department of Agronomy THE.' UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1947. - i - TABLE OF CONTENTS Page Acknowledgement i i I n t r o d u c t i o n 1 Review of L i t e r a t u r e 2 Methods 4 Area Studied 6 Vegetation of the Brown S o i l Zone 7 Vegetation of the Dark Brown S o i l Zone 10 Vegetation of the Black S o i l Zone 10 Vegetation of the Shallow Black S o i l Zone . 12 Vegetation of "the Grey Wooded S o i l Zone ... 12 Experimental Results 21 D i s c u s s i o n 28 A b s t r a c t 40 B i b l i o g r a p h y 41 ACENOWIEX)GSMENT The author wishes t o express h i s g r a t i t u d e to Mr. L. B. Thomson, Superintendent of the Dominion Experimental S t a t i o n , S w i f t Current, Saskatchewan, and to Mr. 1'. W. T i s d a i e , Head of the D i v i s i o n of Forage Crops and Rangeland Research 'at t h a t S t a t i o n , f o r t h e i r co-operation i n f u r - n i s h i n g f a c i l i t i e s f o r the c o l l e c t i o n of samples, and a u t h o r i z i n g the use of records and photographs. A great de a l of c r e d i t i s due t o Dr. V.C. B r i n k , A s s o c i a t e P r o f e s s o r o f Agronomy a t The U n i v e r s i t y of B r i t i s h Columbia, f o r h i s keen i n t e r e s t , which provided i n s p i r a t i o n f o r t h i s problem and f o r h i s valuable guidance through the course of t h i s study. 4 Abstract on p.40 - 1 - COMPARATIVE QUALITY OF PASTURAGE ON WESTERN CANADIAN RANGES INTRODUCTION There i s good reason t o b e l i e v e t h a t the q u a l i t y of range forage i s q u i t e as important as the quantity. While much a t t e n t i o n has been given t o the determination o f dry matter y i e l d per acre of the western range forages, s t u d i e s of t h e i r q u a l i t y have not o f t e n l e d to i n d i c a t i v e conclusions. . Range types i n Western Canada are f a i r l y e a s i l y charac- t e r i z e d by d e f i n i t e v e g e t a t i o n a s s o c i a t i o n s . Broad a s s o c i a - t i o n s of veg e t a t i o n are recognized i n the sh o r t g r a s s , mixed- grass and t a l l g r a s s p r a i r i e s and i n the low, mid- and upper grasslands o f B r i t i s h Columbia. These a s s o c i a t i o n s r e f l e c t d i r e c t l y the s o i l and cli m a t e under which the v e g e t a t i o n develops and c o r r e l a t e w e l l w i t h the major s o i l groupings. Although d i f f e r e n c e s i n dry matter y i e l d s by zones are w e l l e s t a b l i s h e d , v a r i a t i o n s i n q u a l i t y by zone have not been demonstrated. Many forage species i n d i v i d u a l l y have been appraised f o r q u a l i t y , but these.analyses have given l i t t l e i n d i c a t i o n of the zonal p i c t u r e . - 2 - Q u a l i t y estimates, when r e l a t e d t o dry matter y i e l d , are valuable both t o the e c o l o g i s t and the n u t r i t i o n i s t . The e c o l o g i s t can appraise more p r e c i s e l y the value of the d i f f e r e n t ranges, and the s p e c i a l i s t i n n u t r i t i o n obtains a guide f o r r e s e a r c h ' i n animal p r o d u c t i o n . A c c o r d i n g l y , t h i s work was undertaken to assess the q u a l i t y of range forage i n the major zones of the Western Canadian gras s l a n d s . In order to c h a r a c t e r i z e the rangeland types, the y i e l d s of p r o t e i n , calcium and phosphorus were determined. Further s t u d i e s of t h i s nature are necessary and would undoubtedly a s s i s t i n completing the p i c t u r e of the q u a l i t y of vegeta- t i o n i n the d i f f e r e n t zones. REVIEW OF LITERATURE While there are many pu b l i s h e d papers i n the general l i t e r a t u r e on the values of pastures, few of these r e f e r s p e c i f i c a l l y t o the range pastures of the North West. Clarke ejfc J L I (7) have pu b l i s h e d on the v e g e t a t i o n a l composition of the grassland types of Southern A l b e r t a , Saskatchewan, and Manitoba, and have proposed methods of determining the c a r r y i n g c a p a c i t y of those rangelands. In B r i t i s h Columbia, T i s d a l e (39) reported on chemical com- p o s i t i o n and ecology of the g r a s s l a n d p l a n t s . Moss (31) has shown g r a p h i c a l l y the r e l a t i v e abundance of n a t i v e grasses i n the rangelands of Southwestern A l b e r t a . He has a l s o i ncluded extensive d e s c r i p t i v e notes on Bouteloua-Stipa, - 3 - Festuca-Danthonia and Agropyron-Stlpa-Carex a s s o c i a t i o n s . Smith (34) i n a l l i e d a s s o c i a t i o n s proposes methods of e s t i m a t i n g forage y i e l d s of n a t i v e p a s t u r e s . In a recent b u l l e t i n Clarke and T i s d a l e (9) show the chemical composition of i n d i v i d u a l range species of the Canadian p r a i r i e s . D ealing w i t h Manitoba v e g e t a t i o n , B i l l s and C a l d w e l l (15) i n d i c a t e t h a t a l l low-land grass hays of t h a t province are low i n phosphate i f measured by standards used elsewhere, and that l a t e c u t t i n g of hay a f t e r the normal time lowers the phosphate content. Welch (43) reported on m i n e r a l d e f i c i e n c i e s i n forage of Montana range- l a n d s , and Whitman (45) shows chemical analyses of North Dakota grasses. Tables of acreages of grasslands on the Canadian p r a i r i e s are published along w i t h a r e p o r t on p a l a t a b i l i t y and chemical composition of c e r t a i n v e g e t a t i o n of the p r a i r i e s ( C l arke and T i s d a l e 8 ) . A r c h i b a l d (1) s t a t e s that potassium has o n l y minor s i g n i f i c a n c e i n n u t r i t i o n of g r a z i n g animals, and t h i s appears to apply under western c o n d i t i o n s . Other papers deal s p e c i f i c a l l y w i t h the t o t a l forage y i e l d of various types of western v e g e t a t i o n . No r e p o r t s , however, d e a l d i r e c t l y with' forage q u a l i t y i n terms of y i e l d of n u t r i e n t s per acre. 1 - 4 - k METHODS! The o b t a i n i n g of r e p r e s e n t a t i v e samples of ve g e t a t i o n types presents d i f f i c u l t i e s . In t h i s study, s i t e s which were judged to be t y p i c a l of the f a c i a t i o n under c o n s i d e r a t i o n were s e l e c t e d , u s i n g quadrat and p o i n t sampling data obtained from previous work. A l l the s i t e s were l o c a t e d i n such a way t h a t they could be c l i p p e d at about the same stage of m a t u r i t y . S e l e c t i o n r e q u i r e d the p e r u s a l of growth notes accumulated over a p e r i o d o f years.^ A l l types s t u d i e d were c o l l e c t e d i n the e a r l y p a r t of t&e f l o w e r i n g stage of the dominant species of each a s s o c i a t i o n . This i s considered the optimum, time f o r c u t t i n g many grasses f o r hay (30,32). Samples were taken on an acreage y i e l d b a s i s . A quadrat frame, one-half meter (%m2) i n area was used. To minimize personal b i a s , i t was tossed at random i n the s e l e c t e d s i t e . A l l the forage encompassed by the frame was c l i p p e d a t one and one-half (1̂ -) inches above the surface of the s o i l . Grasses and f o r b s (broad-leaved p l a n t s ) were c l i p p e d separate- l y and put i n separate bags. Care was taken to. remove a l l the o l d o r cured growth so th a t the sample represented one season's p r o d u c t i o n . The quadrat was cast 4 to 6 times i n each s i t e and each c l i p was kept in?, a separate c o n t a i n e r . Data c o l l e c t e d by i'orage D i v i s i o n , Dominion Experimental S t a t i o n , S w i f t Current, Saskatchewan. Several s i t e s were s e l e c t e d f o r each zone. The bagged samples were-then plac e d i n a greenhouse and allowed to dry f o r s e v e r a l days under normal c o n d i t i o n s . Weights were taken on a rough balance t o the nearest one- t e n t h gram, and each sample weight was m u l t i p l i e d by a f a c t o r of 17.84 to g i v e a y i e l d i n pounds per acre. A l l variates... (weights i n pounds per acre ) f o r each v e g e t a t i o n type were included i n a s t a t i s t i c a l a n a l y s i s and standard d e v i a t i o n s , means, and standard e r r o r of the means deter- mined. The s t a t i s t i c s are recorded g r a p h i c a l l y to show the degree of accuracy of sampling.(33). The mean y i e l d s are compared w i t h p o i n t sampling y i e l d data and the c o r r e l a t i o n c o e f f i c i e n t g i v e n . For chemical determinations, a l l the m a t e r i a l was ground through a 60-mesh screen i n a Wiley m i l l and was d r i e d t o constant weight at 90 degrees. Crude p r o t e i n was determined on the oven dry samples, u s i n g the K j e l d a h l method e s s e n t i - a l l y as adapted by Loomis and S h u l l ( 22), but u s i n g Hengar granules as a c a t a l y s t . A conversion f a c t o r o f 6.25 was used on n i t r o g e n assays to estimate crude p r o t e i n (32). Phosphorus was determined c o l o r i m e t r i c a l l y (21) and calcium was determined by a standard macro-volumetric procedure ( 3 ) . T o t a l ash was determined by a method of Loomis and S h u l l ( i b i d ) u sing a c o n t r o l l e d muffle furnace. A l l analyses were reported on a b a s i s of oven dry weight p l u s ten per- cent moisture. This was done so t h a t r e s u l t s would be o - 6 - comparable w i t h standard f e e d s t u f f s a n a l y s i s •(30). AREA. STUDIED From Manitoba to C e n t r a l B r i t i s h Columbia, broad s o i l zones can be c h a r a c t e r i z e d on the b a s i s of the c o l o u r of the "A" h o r i z o n . In grasslands of r e l a t i v e l y high e f f e c t i v e moisture^, organic matter tends to accumulate i n the upper s o i l h o r i z o n s . T h i s , i n t u r n , confers on these horizons a b l a c k c o l o u r . As moisture e f f e c t i v e n e n s becomes progress- i v e l y l e s s , the upper horizons assume dark brown to brown co l o u r s . While the zones, "the B l a c k " , "the Dark Brown", and "the Brown", extend broadly across the Western p r o v i n c e s , the v e g e t a t i o n a l a s s o c i a t i o n s or types are much more l i m i t e d . Hence, i n a given s o i l zone, "the B l a c k " , the E a s t e r n f a e i a - ti'ons c o n s i s t of t a l l g r a s s e s , v i z . Andropogons and Panicums; i n the f o o t h i l l s of A l b e r t a , a Festuoa-Danthonia a s s o c i a t i o n develops. On the other hand, the Black s o i l s which charac- t e r i z e the upper grasslands of B r i t i s h Columbia, include F e s t u c a , S t i p a and Poa as dominants. Thus, i n order to o b t a i n r e p r e s e n t a t i v e samples of v e g e t a t i o n from each broad s o i l zone, major v e g e t a t i o n a s s o c i a t i o n s w i t h i n the zone had to be considered. I t i s recognized, of course, t h a t moisture i s not the s o l e f a c t o r c o n d i t i o n i n g t h i s d i f f e r e n t i a l s o i l development. Complex i n t e r a c t i o n s o f moisture, temperature and vegeta^ t i o n are r e s p o n s i b l e . BROW SOIL ZONE* In the Brown s o i l zone, v e g e t a t i o n from f i v e major a s s o c i a t i o n s was c o l l e c t e d . These a s s o c i a t i o n s are: Short- g r a s s , S a n d h i l l , Sceptre, H a v e r h i l l , a l l of A l b e r t a and Saskatchewan, and the Lower Grassland of B r i t i s h Columbia. Of the zones considered, the Brown s o i l zone has developed under the lowest r a i n f a l l . I t i s c h a r a c t e r i z e d by a r e l a t i v e l y low organic matter content and by a l i g h t brown "A" h o r i z o n . The upper, h o r i z o n i s i n v a r i a b l y shallow w i t h a l a y e r , at a depth of s i x to fourteen inches, of hardpan w i t h a high calcium content (29). (a) Shortgrass p r a i r i e The Shortgrass p r a i r i e occupies the southwestern s e c t i o n of Saskatchewan and the southeastern p o r t i o n o f Alberta.. I t comprises a l a r g e p r o p o r t i o n of the Brown S o i l Zone. This a s s o c i a t i o n has developed i n areas which have a very low e f f e c t i v e p r e c i p i t a t i o n . The r a i n f a l l i s l e s s than fourteen inches per annum and the evaporation rate i s high ( 9 ) . In the f a c i a t i o n , the dominant species which comprises about 61.8 percent of the t o t a l grass cover i s Boiiteloua • g r a c i l i s (blue grama g r a s s ) . S t i p a comata (needle-and- thread grass) i s a sub-dominant grass which makes up about 24 percent of the grass cover. Other cognate species of grasses and herbs are given i n Tables I , , I I and I I I . - 8 - (b) S a n d h i l l The S a n d h i l l f a c i a t i o n i s found i n the region of the Great S a n d h i l l s of Southern Saskatchewan. I t comprises the v e g e t a t i o n growing i n the sandy.areas which are s t a b i l i z e d . The samples reported on are from both medium tex t u r e d and sandy s o i l s . The grasses i n the sample are p a l a t a b l e , but t h e i r y i e l d i s poor (Table I ) . The f o r b s and shrubs, which produce a r e l a t i v e l y heavy cover, however, are quite u n p a l a t a b l e . The shrubs were not included i n the samples. (c) Sceptre p r a i r i e This f a c i a t i o n i s found on heavy t e x t u r e d s o i l s developed on uniform c l a y deposits occupying the beds of former g l a c i a l l a k e s (29). As the s o i l s are h i g h l y p r o d u c t i v e , the acreage remaining i n n a t i v e pasture i s s m a l l . Most of the a r a b l e l a n d i s used f o r the p r o d u c t i o n of c e r e a l crops. The e c o l o g i c a l p r i n c i p l e , t h a t fewer n a t i v e species are found on the more p r o d u c t i v e s o i l s , i s w e l l i l l u s t r a t e d i n a study of the species composition of t h i s f a c i a t i o n . Hence the grass cover i s made up of o n l y three co-dominants, Agropyron dasystachyum (northern wheatgrass), K o e l e r i a c r i s t a t e (june- grass) and S t i p a v i r i d u l a (green speargrass). There are few f o r b s of importance. (d ) H a v e r h i l l p r a i r i e This v e g e t a t i o n a l type covers approximately one-half of the area of the Brown s o i l zone and c o n s t i t u t e s the l a r g e s t u n i t of "mixed p r a i r i e " . The species found i n H a v e r h i l l p r a i r i e v e g etation are "both short and medium-tall grasses forming a mixture which marks a t r a n s i t i o n between the shortgrass and t a l l g r a s s p r a i r i e s . The p r i n c i p a l grasses i n order of importance are: S t i p a spartea var. c u r t i s e t a (short-awned porcupine g r a s s ) , K o e l e r i a c r i s t a t a ( j u n e g r a s s ) , Agropyron spp. (wheatgrasses), and Bouteloua g r a c i l i s (blue grama grass) (See Table I I ) . The above, types c o n s t i t u t e t y p i c a l f a c i a t i o n s i n the Brown S o i l Zone of the P r a i r i e P r o v i n c e s . There are many other v e g e t a t i o n a l a s s o c i a t i o n s withimi the zone", but none of these i s s u f f i c i e n t l y d i f f e r e n t or important t o warrant a s p e c i a l d e s i g n a t i o n here. The samples from the above areas •were c o l l e c t e d from the S w i f t Current D i s t r i c t i n Southern Saskatchewan. (e) B.C. Lower Grassland To show a comparison of v e g e t a t i o n of the Brown s o i l s of the p r a i r i e s and the Brown s o i l s of B r i t i s h Columbia, samples were c o l l e c t e d from the Lower Grasslands at Kamloops, B.C. This type i s between 1200 and 2100 f e e t a l t i t u d e , i n a zone of low p r e c i p i t a t i o n and high summer temperatures. The p l a n t cover i s sparse and composed c h i e f l y of Agropyron spicatum (bluebunch wheatgrass), S t i p a comata (needle-and- thread g r a s s ) , Sporobolus cryptandrus (sand dropseed), and Poa secunda (Sandberg's b l u e g r a s s ) . Artemesia t r i d e n t a t a - 10 - (sagebrush) o f t e n appears t o be co-dominant w i t h the above grasses. Most of the lower grasslands have been overgrazed, but the v e g e t a t i o n from the areas s e l e c t e d f o r sampling approaches the o r i g i n a l climax cover of the lower grasslands. DARK BROWN SOIL ZONE The s o i l s of t h i s zone have a darker brown c o l o u r , probably because of t h e i r s l i g h t l y higher organic matter content. The zone enjoys somewhat higher r a i n f a l l and a lower evaporation r a t e than the Brown S o i l zone. The veg e t a t i o n makes a denser cover, and t a l l e r growth and, i n favourable areas, s m a l l " b l u f f s " o f t r e e s and shrubs are found, forming parklands. The c h i e f species of t h i s zone are Agropyron spp. (wheatgrasses), Festuca s c a b r e l l a (rough f e s c u e ) , K o e l e r i a c r i s t a t a ( j u n e g r a s s ) , S t i p a comata (needle- and-thread g r a s s ) , S t i p a spartea car, c u r t i s e t a (short-awned porcupine g r a s s ) , Festuca idahoensis (Idaho f e s c u e ) , and Poa p r a t e n s i s (Kentucky b l u e g r a s s ) . In B r i t i s h Columbia, a p r i n c i p a l f o r b of the Dark Brown area i s Balsamorhiza s a g i t t a t a (balsamroot). BLACK SOIL ZONE The Black S o i l zone of the p r a i r i e s i s c o i n c i d e n t w i t h the area commonly spoken of as "the Park B e l t " . The r a i n f a l l i s higher and evaporation r a t e lower than i n the Dark Brown zone. The s o i l s are very dark i n colour and support a l u s h growth of v e g e t a t i o n . Although the s o i l s i n t h i s zone are - 11 - fundamentally g r a s s l a n d s o i l s , " b l u f f s " of t r e e s are very numerous. The area s e l e c t e d f o r sampling i n A l b e r t a was i n the f o o t h i l l s r e g i o n , west of Muirhead, A l b e r t a . Here the dominant species are: Festuca s c a b r e l l a (rough f e s c u e ) , Danthonia P a r r y i (Parry*s o a t g r a s s ) , and K o e l e r i a c r i s t a t a ( j u n e g r a s s ) . The p r i n c i p a l f o rb i s P o t e n t i l i a f r u i t i c o s a (shrubby c i n q u e f o i l ) . Samples r e p r e s e n t i n g v e g e t a t i o n of the Black S o i l s of Manitoba were c o l l e c t e d near Balmoral. Two types were sampled; One of* them, the n a t i v e t a l l g r a s s p r a i r i e a s s o c i a - t i o n , i s made up p r i n c i p a l l y of Andropogon f u r c a t u s ( b i g bluestem), Andropogon scoparious ( l i t t l e bluestem) , Panicum virgatum (switchgrass) and S t i p a spartea (porcupine g r a s s ) . The other type i s made up p r i m a r i l y of Poa p r a t e n s i s (Ken- tucky b l u e g r a s s ) , which has invaded the n a t i v e pastures and now e x i s t s i n n e a r l y pure stands. Samples of t h i s invader, were c o l l e c t e d i n order to compare i t with the n a t i v e species, i n reference to y i e l d and q u a l i t y . The Black S o i l s area s e l e c t e d i n Saskatchewan was i n the high l e v e l s of the Cypress H i l l s . The p r i n c i p a l forage species are Festuca s c a b r e l l a (rough f e s c u e ) , Danthonia intermedia ( w i l d o a t g r a s s ) , and Agropyron trachycaulum (awned wheatgrass). Again, P o t e n t i l l a f r u i t i c o s a (shrubby cinquefoil). i s the p r i n c i p a l f o r b . In B r i t i s h Columbia, the Black S o i l s occur a s s o c i a t e d - 12 - w i t h the upper grassland between the a l t i t u d e s of 2800 and 3100 f e e t . There i s a dense cover of grasses here s i m i l a r t o those i n the Black S o i l s of the Cypress H i l l s . S t i p a , columbiana (Columbia needlegrass) i s found i a a d d i t i o n t o those grasses mentioned f o r the Black S o i l s of-the Cypress H i l l s . A l s o , the cover of f o r b s i s important and may con- s t i t u t e a major p o r t i o n of the grazable forage. SHALLOW BLACK SOIL ZONE This zone marks a t r a n s i t i o n between the Dark Brown and Black S o i l s zones i n A l b e r t a . The r e l a t i v e l y shallow nature of the "A" h o r i z o n has r e s u l t e d from a h i g h rate o f evapora- t i o n and a l s o a f a i r l y h igh i n i t i a l l i m e content of the parent s o i l (48). These s o i l s are p r a c t i c a l l y a l l g r a s s l a n d s o i l s i n t h e i r n a t i v e s t a t e . The p r i n c i p a l forage species are Danthonia P a r r y i (Parry's oatgrass) and Festuca s c a b r e l l a (rough f e s c u e ) . The re g i o n s e l e c t e d f o r sampling was west of Cochrane, A l b e r t a . GREY WOODED SOIL ZONE Samples of forage from t h i s zone were taken from the lower Montane F o r e s t zone (3000 to 4200 f e e t a l t i t u d e ) i n the Kamloops d i s t r i c t . Samples were taken f o r comparative purposes.only and may mot be r e p r e s e n t a t i v e of a l l Grey Wooded v e g e t a t i o n . The grass cover i s made up almost e n t i r e l y .of Calamagrostis rubescens ( p i n e g r a s s ) . The • more important f o r b s are A s t e r conspicuus (showy a s t e r ) , - 13 - Lathyrus ochroleucus (pea v i n e ) , V i o i a americana (American v e t c h ) , A s t r a g a l u s s e r o t i n u s (timber m i l k - v e t c h ) , and A r n i c a c o r d i f o l i a ( a r n i c a ) . Table I shows the b o t a n i c a l composition of the grass sward i n the s e v e r a l v e g e t a t i o n a s s o c i a t i o n s . " S t i p a u n i t s " express the percentage cover of each grass on a comparable b a s i s ( 7 ) . I n the determination of these forage u n i t s , , a l l grasses are given values r e l a t i v e to S t i p a comata, g i v i n g i t a value of 1.0. The y i e l d i n pounds per acre i s based on p o i n t sampling data, assuming t h a t a cover of 100 percent S t i p a comata y i e l d s 5000 pounds of dry matter per acre ( 7 ) . The " R e l a t i v e percentage" column shows the r e l a t i v e amounts of each species i n the t o t a l grass cover, based on p o i n t sampling o n l y . Table I I shows the b o t a n i c a l composition of the f o r b s f r a c t i o n i n the d i f f e r e n t a s s o c i a t i o n s . I t w i l l be n o t i c e d t h a t a l l of the a s s o c i a t i o n s do not have b o t a n i c a l data* The y i e l d data i n Table I I w i l l be r e f e r r e d t o l a t e r . TABLE I x The R e l a t i v e Percentage B o t a n i c a l Composition of Range Types and the Y i e l d of Bach Type FORAGE SPBCHES SHORTGRASS PRAIRIE SANDHILL SCEPTRE PRAIRIS? HAVE] PRA RHLLL IRLE SASKATCHEWAN DARK BROWN Stipa. u n i t s R e l . f° S t i p a u n i t s R e l . f* S t i p a u n i t s R e l . S t i p a u n i t s R e l . S t i p a u n i t s R e l . * Agropyron dasystachyum .35 6.13 .04 .62 5.81 59.34 2.00 17.06 .07 .64 Agropyron S m i t h i i .21 3.22 .60 6.13 .08 .68 3.71 33.70 Agropyron trachycaulum .17 .64 Avena Hookeri Bouteloua g r a c i l i s 3.53 61.82 1.88 28.80 .93 7.93 .58 5.27 Calamagrostis montanensis .01 .09 • C a l a m a v i l f a l o n g i f o l i a .01 .11 Danthonia intermedia .07 .64 p Danthonia P a r r y i i F estuca idahoensis Festuca s c a b r e l l a .06 .52 .42 3.80 K o e l e r i a c r i s t a t a .14 2.45 .03 .46 2.13 21.75 1.37 11.68 1.16 10.54 Poa secunda .03 .53 .01 .14 Poa spp. .03 .26 .03 .27 Sporobolus cryptandrus .22 3.38 S t i p a comata 1.40 '24.51 3.05 46.71 1.96 16.72 .35 3.18 S t i p a spar t e a var. curt i seta .14 2.45 .77 11.80 3.70 31.57 2.87 26.07 S t i p a v i r i d u l a 1.14 11.65 .04 .34 Carex f i l i f o l i a .12 2.11 .31 4.76 Carex h e l i o p h i l a 1.68 15.25 Carex spp. Juncus a t e r I'urotia l a n a t a .11 1.14 TOTAL FORAGE UNITS 5.71 6.53 9.79 10.18 11.01 NUMBER POINTS TAKEN 2000 4800 5500 5600 4000 YHLD IN POUNDS PER ACRE" 285 326 489 509 550 Data c o n s i s t s p a r t l y of records of past years c o l l e c t e d at S w i f t Current, Sask Table I ( continued) ALBERTA DARK BROWN SASK. BLACK ALBERTA BLACK ALTA. B: SHALLOW LACK S t i p a u n i t s R e l . S t i p a u n i t s R e l . % S t i p a u n i t s R e l . S t i p s u n i t s R e l . % Agropyron dasystachyum Agropyron S m i t h i i Agropyron trachycaulum Avena Hookeri Boiiteloua g r a c i l i s Calamagrostis montanensis Cala m a v i l f a l o n g i f o l i a Danthonia intermedia Danthonia P a r r y i Festuca idahoensis Festuca s c a b r e l l a K o e l e r i a c r i s t a t a Poa secunda Poa spp. Sporobolus cryptandrus S t i p a comata S t i p a spartea var. c u r t i s e t a S t i p a v i r i d u l a C a r e x . f i l i f o l i a Carex spp. Carex h e l i o p h i l a Juncus a t e r E u r o t i a l a n a t a 8.16. 2; 98 2.79 17.06 25.62 23.99 .08 .92 .07 .49 15.28 .03 • .46 1.98 .09 .41 4.74 .36 2.53 78.76 .15 2.37 10.22 .46 7.81 18.90 2.70 26.55 64.27 9.18 10.08 1.21 92.59 7.41 TOTAL FORAGE UNITS 11.63 19.40 29.41 15.12 NUMBER POINTS TAKEN 2000 3000 2000 2000 YIELD IN FOUNDS PER ACRE I 581 970 1470 756* TABLE I I • ' i The R e l a t i v e Percentage B o t a n i c a l Composition of Forbs i n the D i f f e r e n t Range Types 1 SPECIES RELATIVE PERCENTAGE' OF TOTAL FORBS SHORT- GRASS SANDHILL SCEPTRE HAVER- HILL SASK. DARK BROWN SASK. BLACK A c h i l l e a l a n u l o s a .88 Antennaria m i c r o p h y l l a 1.23 Artemesia cana 33.33 3.05 1.64 Artemesia f r i g i d a 26.93 73.70 13.58 7.39 68.86 .90 A t r i p l e x N u t t a l l i i . 1.64 Cerastium campestre 1.79 Chenopodium leptophyllum 2.54 G u t i e r r e z i a d i v e r s i f o l i a .38 Lithospernum l i n a e r i f o l i u n .64 Malvastrum coccinium .38 .24 Phlox H o o d i i 1.93 6.79 3.15 P o t e n t i l i a f r u i t i c o s a 76.71 P s o r a l e a l a n c i o l a t a .38 Rosa spp. .64 5.08 .86 S e l a g i n e l l a densa 30.77 5.34 78.90 27.86 9.85 S i e v e r s i a t r i f o l i a 2.99 Solidago glaberrima .24 3.88 Carex e l e o c a r i s 2 5.76 9.15 77.78 9.21 TOTAL PERCENTAGE LOO.00 100.00 100.00 100.00 100.00 100.00 t e l a t i v e percentage of t o t a l f o r b cover. 8Care%. e l e o c a r i s . i n c l u d e d w i t h th§ f o r b s Data Bartly^compiled^from records a t as I l 7 l H no I iUven a forage r a t i n g but Dom. S x p t / S t a . , S w i f t Current, Sask. constitutes a major p o r t l o f i o f the caver. - 17 - PLATE I I . S a n d h i l l f a c i a t i o n - 18 - PLATE IV. H a v e r h i l l (mixed) p r a i r i e f a c i a t i o n . - 19 - PLATE V I I I . B r i t i s h Columbia Grey Wooded. (Montane f o r e s t ) - 21 - EXPEPJME'NTAL RESULTS F i g u r e I i l l u s t r a t e s the dry matter y i e l d s of forage on d i f f e r e n t s o i l types, obtained by c l i p p i n g . The s o l i d s e c t i o n s of the bars i n d i c a t e the grass y i e l d s and the cross- hatched p o r t i o n s i n d i c a t e the forb y i e l d s . The complete bars show t o t a l y i e l d s of the a s s o c i a t i o n s . The'graph shows the p r o g r e s s i v e l y higher production from the Brown S o i l zone to the Black S o i l zone. I t also i n d i c a t e s the f a c t t h a t r e l a t i v e - l y fewer f o r b s occur as the more p r o d u c t i v e zones are approached. For purposes of comparison, y i e l d s obtained from p o i n t sampling data are, as aforementioned, given i n Table I . Figur e I I i s used t o show the accuracy of dry matter sampling. I t employs three s t a t i s t i c s : > the mean y i e l d per acre (the centre cross bar of each graph); the sampling range (the l e n g t h of the bar above and below the mean); and the t h e o r e t i c a l sampling range (the cross-hatched p o r t i o n ) . The t h e o r e t i c a l range i s represented as twice the standard e r r o r above and below the mean '(33). In a s s o c i a t i o n s where the t h e o r e t i c a l range approaches the sampling range (e.g., Sceptre p r a i r i e ) , the sampling i s o b v i o u s l y more accurate. In the Shortgrass p r a i r i e a s s o c i a t i o n s , f o r example, the sampling range appreciably exceeds the t h e o r e t i c a l range. Thus, t h i s sampling may not be r e p r e s e n t a t i v e . The graph f o r forage from the higher y i e l d i n g types (e.g., A l b e r t a f o o t h i l l s ) shows - 22 - a l a r g e d i f f e r e n c e between a c t u a l and h y p o t h e t i c a l ranges. In t h i s case i t i s not s e r i o u s because the forage y i e l d i s over twice as great as the Shortgrass y i e l d , and the e r r o r i s t h e r e f o r e no g r e a t e r . I t must be borne i n mind t h a t i f the c o e f f i c i e n t of v a r i a b i l i t y were used, the higher y i e l d i n g a s s o c i a t i o n s would show a lower r e l a t i v e e r r o r . The p o i n t sampling y i e l d s were c o r r e l a t e d w i t h the dry matter y i e l d s of Figures I and I I . A p o s i t i v e c o r r e l a t i o n of 0.91 was obtained. A c c o r d i n g l y , i t can s a f e l y be assumed th a t dry weight sampling as conducted i n these experiments would agree w i t h more extensive samplings by the P o i n t Technique. Table I I I designates the r e s u l t s of chemical analyses of the forage. The percentage i s given f o r p r o t e i n , calcium, phosphorus and ash. The y i e l d s of the above c o n s t i t u e n t s w i t h w the exception of ash are expressed i n pounds per acre. Table IV gives the same data arranged t o show d i f f e r e n c e s i n con- s t i t u e n t y i e l d s between the major zones. A very marked increase i n the production of p r o t e i n , c a l - cium and phosphorus from the Brown S o i l s to the Black S o i l s i s demonstrated. The data f o r Shallow B l a c k , Grey Wooded and A l l u v i a l S o i l s are few and hence should only be used f o r broad comparison. In-each type, the grass c h a r a c t e r i z e s the pro- d u c t i v i t y and q u a l i t y more a c c u r a t e l y than the f o r b s . Hence, the data f o r grasses and f o r b s are given s e p a r a t e l y . A l s o , the analyses f o r the broadleaved v e g e t a t i o n are more v a r i a b l e and may be misleading i f they are, used alone. FIGURE I Graph showing Y i e l d s of Forage per acre f o r a l l Vege-t a t i o n a l A s s o c i a t i o n s s t u d i e d . X S o l i d p o r t i o n of par,. de-plots grass y i e l d ; cross-hatched p o r t i o n - f o r t ) y i e l d ) G R O S S Y I E L D I N P O U N D S P E R A C R E INI - w CJ - J <S - O i » - J (O _ o o o o o ° o o o o 9 o o . o o o ° o o o o 9 J I I I : I _ J i ' I I L v \ \ \ \ \ \ \ \ \ \ \ \ \ SHORTGRASS PRAIRIE (BROWN) SANDHILL (BROWN) SCEPTRE PRAIRIE—(BROWN) HAVERHILL PRAIRIE (BROWN) B.C. LOWSRASS (CRESTED WHEAT) B.C. LOWSRASS (NATIVE) SASKATCHEWAN (DARK BROWN) ALBERTA FOOTHILLS (OK BROWN) B.C. MID GRASS (DARK BROWN) ALBERTA FOOTHILLS (BLACK) SASKATCHEWAN (BLACK) I B.C. UPPER GRASS (BLACK) wwwwwwwwwwwv wwwwww ALBERTA FOOTHILLS (SHALLOW BLACK) . vwwwwvwv ' B.C. MONTANE FOREST (GREY WOODED) SASKATCHEWAN ALLUVIUM (NATIVE) SASKATCHEWAN ALLUVIUM (BROMEJ MANITOBA "BLUEGRASS0 (BLACK)' | MANITOBA. TALLGRASS (BLACK) i 1 ~ i 1 1 1 n 1 — ; — i 1 r — OI ( M - 4 <D — O i — O O o o o o o o o o o O O o O O O O O O O O O R O S S Y I E L D I N P O U N D S P E R A C R E - .24 - F I G U R E : I I Y I E L D I N P O U N D S P E R A C R E Q o u o o «• o p o o _ U o o _ 1 _ o o u o o o o o o J_ ID o . o tO to K ^ V I I SHORTGRASS PRAIRIE SANDHILL SCEPTRE PRAIRIE (MIXED) I RftftW I HAVERHILL PRAIRIE (MIXED) B.C. LOWGRASS (CRESTED WHEAT) B.C. LOWGRASS (NATIVE) l \ \ \ \V WWWV l \ \W\ \ \ \ \ ^8 SASKATCHEWAN (CYPRESS HILLS) | ALBERTA (FOOTHILLS) tz \W> WW I WW \ \W B.C. (MIDGRASS) to g CO vWV WW 1 ALBERTA (FOOTHILLS) K\\\\^v\\\\l SASKATCHEWAN (CYPRESS HILLS) B.C. (UPPER GRASSLAND) 5 to £ to * • ^ ALBERTA (FOOTHILLS) IWWV vWWNI •1 \wwww wwww; B.G. (MONTANE FOREST) 1% to £ t o * I www \\\\>s SASKATCHEWAN (NATIVE) SASKATCHEWAN' feWBWD (CULTIVATED BROMEGRASS) O o M - O o o o o o o o o o o o 0 o o o o s Y I E L D I N P O U N D S P E R A C R E / TABLE I I I The Chemical Composition of the Grassland A s s o c i a t i o n s and the Con s t i t u e n t , Y i e l d s per Acre. ( R e s u l t s , ' M o i s t u r e - f r e e p l u s 10$.) SOIL ZONE VEGETATION ASSOCIATION FORAGE YIELD lb./A PROTEIN • CALCIUM PHD SPED HOE ASH f" Ca:P RATIO lb./A lb./A * ]b./A BROW Shortgrass p r a i r i e Grass Forbs T o t a l 218 105 323 10.37 10.73 22.6 11.2 . 33.8 .50 .79 1.1 .8 1.9 .18 .28 .4 .3 -.7 6.60 6.66 2.75- 2.67 2.71 •1 :1 :1 S a n d h i l l Grass Forbs T o t a l 305 286 591 9.81 10.26 29.9 29.3 .41 .85 1.2 2.4 3.6 .19 .06 .6 .2 5.99 11.97 1.97: 12.00: 4.50: 1 1 1 59.2 Sceptre p r a i r i e Grass 337 9.05 30.5 .50 1.7 .24 .8 8.56 2.12: 1 H a v e r h i l l p r a i r i e Grass Forbs T o t a l 452 61 513 9.63 9.67 43.5 5.9 49.4 .38 .74 1.7 .4 2.1 .18 .30 .8 .2 1.0 7.21 5.92 2.12: 2.00: 2.10: 1 1 1 B.C. Low&rass 1 Grass 584 5.60 32.7 .28 1.6 .23 1.3 8.77 1.23: 1 B.C. Lowgrass 2 Grass 717 8.82 63.2 .23 1.6 .22 1.6 11.67 1.00: a DARK BROWN Sask. (Cy- press H i l l s ) Grass Forbs T o t a l 472 70 542 7.20 8.55 34.0 6.0 40.0 .31 .79 1.5 .6 2.1 .22 .11 1.0 .1 1.1 8.76 6.91 1.50" 6.00 1.91 :1 ! l 1 A l b e r t a (Foot- h i l l s ) Grass Forbs Total 691 "49 740 7.70 8.73 53.2 4.3 57.5 .19 .82 1.3 .4 1.7 .18 .19 1.2 .1 1.3 8.61 6.44 1.08" 4.00: 1.31 1 i 1 B.C. (Mid- grass) Grass Forbs T o t a l • 886 93 6.37 5.15 56.4 5.8 .34 .28 3.0 .3 .19 .08 1.7 .1 1.8 10.29 14.06 .1.76< 3.00 1.83 1 ,1 1 979 61.2 3.3 1 C r e s t e d wheatgrass ( r e s e e d e d ) ( C o n t i n u e d ) 2 N a t i v e Table I I I (continued) SOIL ZONE? VEGETATION ASSOCIATION FORAGE' YIELD lb./A P r Dtein Calciun Phosphorus ASH TJa:P RATIO •t lb./iS lb./A $ 3b./A fo . BLACK A l b e r t a (Foot- h i l l s ) Grass Forbs T o t a l 789 484 1273 6.65 9.95 52.5 4.8 57.3 .31 1.98 2.4 9.6 12.0 .16 .17 1.3 .8 2.1 7.28 7.21 1.94:1 12.00:1 4.78:1 Sask. (Cypress H i l l s ) Grass Forbs T o t a l 998 43 1041 6.70 10.00 66.9 4.3 .29 1.45 2.9 .6 3.5 .19 .18 1.9 .1 11.01 8.34 1.53:1 6.00:1 1.77:1 71.2 2.0 B.C.(Upper- Grass) T o t a l 1150 6.29 72.3 .32 3.7 .21 2.4 9.93 1.54:1 Manitoba T a l l g r a s s 1 T o t a l 1330 9.91 131.8 .28 3.7 .15 2.0 6.91 1.85:1 Manitoba T a l l g r a s s 2 T o t a l 1645 6.08 100.0 .23 3.8 .13 2.1 7.23 1.81:1 SHALLOW BLACK A l b e r t a (Foot- h i l l s ) Grass Forbs T o t a l 1364 262 1626 6.64 7.63 90.6 20.0 110.6 .23 1.34 3.1 3.5 6.6 .10 .28 1.4 .7 2.1 5.53 6.15 2.21:1 5.00:1 3.14:1 GREY WOODED B.C. (Montane Forest) Grass Forbs T o t a l 347- 54 401 6.40 9.77 22.2 5.3 27.5 .13 1.18 .4 .6 1.0 .20 .36 .7 .2 .9 18.28 9.61 .57:1 3.00:1 1.11:1 ALLU- VIAL Sask. 3 Grass Forbs T o t a l 672 139 811 9.47 9.81 63.6 13.6 .28 .•59 1.9 .8 2.7 .21 .19 1.4 .3 7.86 5.74 1.36:1 2.67:1 1.58:1 77.2 1.7 Sask. 4 Grass 1123 6.29 70.6 .40 -4.5: .16 1.8 8.05 2.50:1 •••Invaded by Kentucky bluegrass Native 3 N a t i v e ^Bromegrass (reseeded) - 27 - T A B L E T I V The Y i e l d of N u t r i e n t s per Acre by Major S o i l Zone SOIL ZONI? NUMBER SITES NUMBER SAMPLES PROTEIN lb/A CALCIUM lh-/A PHOS- PHORUS l b Ik FORAGE YIELD lb/A Ca:P RATIO BROWN Grass Forbs T o t a l 11 48 37.0 7.7 44.7 1.5 .6 2.1 .9 .1 1.0 435 75 510 1.67:1 6.00:1 2.10:1 DARK BROWN Grass . Forbs T o t a l 4 24 47.9 4.9 52.8 1.9 .4 2.3 1.3 .1 1.4 683 70 753 1.46:1 4.00:1 1.64:1 BLACK G r a s s 1 Forbs^ T o t a l 3 6 36 59.7 4.5 85.6 2.6 5.3 1.6 2.1 893 1288 1.62:1 2.52:1 SHALLOW BLACK Grass Forbs T o t a l 2 8 90.6 20.0 110.6 3.1 3.5 6..6 1.4 . .7 2.1 1364 262 1626 2.21:1 5.00:1 3.14:1 GREY WOODED Grass Forbs Total*-" 2 12 22 • 2 5.3 27.5 ,4 .6 1.0 .7 .2 .9 347 54 401 .57:1 3.00:1 1.11:1 ALLUVIAL Grass •Forbs T o t a l 4 2 8 63.6 13.6 77.2 1.9 .8 2.7 1.4 .3 1.7 672 139 • 811 1.35:1 2.67:1 1.59:1 C u l t i - vated g r a s s 5 70.6 4.5 1.7 1123 2.50:1 'Average f o r A l b e r t a and Saskatchewan Black S o i l Zone. 3Average of T o t a l Forage of a l l A s s o c i a t i o n s i n Black S o i l Zone 4 N a t i v e Vegetation. 5Bromegrass on same s o i l type as 4. - 28 - DISCUSSIQg Table I I I contains the data f o r a l l of the grassland a s s o c i a t i o n s * . Throughout the d i s c u s s i o n , however, the same data are reorganized f o r easy a p p r a i s a l and f o r c l e a r e r development of the'zonal p i c t u r e . Calcium. The Calcium percentage f o r the v e g e t a t i o n of the major zones does not c o r r e l a t e s i g n i f i c a n t l y w i t h r a i n f a l l or s o i l type. In pounds per acre, the calcium, as shown i n Table V, increases from the Brown S o i l s to the Black. The forbs i n the Shallow Black zone, i t can be seen, show a high calcium y i e l d . This may be ass o c i a t e d w i t h the calcium carbonate l a y e r which l i e s o n l y a few inches below the surface of the s o i l . TABLE V The Percentage and Y i e l d of Calcium by Major S o i l Zone SOIL ZONE GRASS FORBS TOTA] L FORAGE % Ca. lb/A Ca. % Ca. lb/A Ca. % Ca. lb/A Ca. BROWN .35 1.8 .82 .6 - .42 2.1 DARK BROWN .28 1.9 .58 .4 : .31 2.3 BLACK .30 2.6 .25 5.3 SHALLOW BLACK .23 3.1 1.34 3.5 .40 6.6 GREY WOODED -.13 .4 1.18 .6 .27 1.0 ALLUVIUM .28 1.9 .59 .8 .34 2.7 Watkins s t a t e s (42) that the calcium content of forage must not f a l l below 0.25 percent f o r the normal n u t r i t i o n a l - 29 - requirement .of animals. With the exception of the grasses of the Grey Wooded zone, none of the zonal forage t e l l s a s t o r y of calcium d e f i c i e n c y . In the Grey Wooded zone, > however, the calcium content of the many p a l a t a b l e forbs i s high. Hence, there may a c t u a l l y be no calcium d e f i c i e n c y i n the grazed forage of t h i s zone. D a n i e l s t a t e s (13) that when the e f f e c t i v e r a i n f a l l i s low, the calcium content of the forage i n c r e a s e s and the phosphorus content decreases. This may account f o r the high calcium content of the grasses of the Sceptre, Shortgrass and S a n d h i l l a s s o c i a t i o n s which are a l l i n a r e g i o n o f extremely low e f f e c t i v e p r e c i p i t a t i o n . , Phosphorus The phosphorus percentage shows a zonal decrease from - the Brown to the Black s o i l s (Table 71). On the other.hand, the y i e l d i n pounds per acre i s p r o g r e s s i v e l y g r e a t e r from the Brown s o i l s to the Black s o i l s . The phosphorus content of forage p l a n t s f o r g r a z i n g animals, commonly accepted as a minimum, i s 0.12 percent (38). None of the samples on t h i s b a s i s , w i t h the exception of the Shallow Black s o i l s vegeta- tion., shows a d e f i c i e n c y of phosphorus at the stage of develop- ment at which they were c l i p p e d . At m a t u r i t y , however, the a s s o c i a t i o n s which have the lowest phosphorus content accord- ing to the data presented would probably be s e r i o u s l y deficient. This -: i s borne out i n the l i t e r a t u r e where statements are made of s e r i o u s phosphorus d e f i c i e n c i e s im c e r t a i n Shortgrass - 30 - pastures (9,43,44) arid Manitoba meadows (15). Too much emphasis should not be placed on phosphorus and calcium percentages considered s i n g l y . The r a t i o of calcium to phosphorus i s h i g h l y important. In g e n e r a l , a r a t i o between 2:1 and 1:2 i s considered optimum f o r animal n u t r i t i o n . Although the phosphorus percentage i n most of the a s s o c i a t i o n s sampled does not appear to warrant concern, the calcium to phosphorus r a t i o i n some of the types i s danger- o u s l y wide. Phosphorus d e f i c i e n c y must occur at times i n the Brown and Shallow Black zones where the calcium to phosphorus r a t i o s are very wide, even i n immature forage. (Table VTI). Greaves (17), i t might be added, has found that t o t a l phosphorus i s a general i n d i c a t o r of the n u t r i t i v e value of the p l a n t . .Phosphorus c o r r e l a t e s n e g a t i v e l y w i t h ash content and p o s i t i v e l y w i t h p r o t e i n content. C o r r o b o r a t i o n of these- f a c t s i s found i n the data i n Table I . I t i s of i n t e r e s t , a l s o , t o note t h a t Greaves ( i b i d ) f i n d s high ash content associated w i t h low crude f a t , and f a t and carbohydrate a s s o c i a t e d w i t h a decrease i n calcium content. This shows tha t the n u t r i t i v e values of high calcium p l a n t s are as a r u l e lower than low calcium p l a n t s . There i s a high c o r r e l a - t i o n between ash and calcium, ash and magnesium, ash and s u l f u r , and a negative c o r r e l a t i o n between calcium and n i t r o g e n - f r e e - e x t r a c t , phosphorus and crude f i b r e and crude f i b r e and crude p r o t e i n (17). - 31 - TABLE VI . Percentage and Y i e l d of Phosphorus by Major S o i l Zone SOIL 'ZONE- PHOSPHORUS Grass 'Porbs T o t a l % lb/A lb/A lb/A BROWN .21 .9 .15 .1 .20 1.0 DARK BROWN .19 1.3 .11 .1 .18 1.4 BLACK .18 1.6 • .16 2.1 SHALLOW BLACK .16 1.4 .28 .7 .13 2.1 GREY WOODED .20 .7 .36 .2 .22 .9 ALLUVIUM .21 1.4 .19 .3 .20 1.7 TABLE V I I Calcium-Phosphorus R a t i o s by Major S o i l Zone SOIL ZONE GRASS FORBS TOTAL FORAGE BROWN 1.67:1 6.00:1 2.10:1 DARK BROWN 1.46:1 4.00:1 1.64:1 BLACK 1.62:1 2.52:1 SHALLOW BLACK 2.21:1 5.00:1 3.14:1 GREY WOODED 0.57:1 3.00:1 1.11:1 ALLUVIUM 1.35:1 2.'67:1 1.59:1 P r o t e i n Many i n t e r e s t i n g conclusions may be drawn from the r e s u l t s of the n i t r o g e n assays. I t has been common p r a c t i c e "in the past to r a t e a l l range pastures e q u a l l y i n reference to the production of n u t r i e n t s . Thus one f i n d s l i t t l e r e l a t i o n s h i p . o f the gr a z i n g charges on rangelands to t h e i r p r o d u c t i v i t y . I t was shown th a t the grasses o f the d r i e r areas possessed a higher p r o t e i n percentage than those of the - 32 - more humid, areas. I t was erroneously b e l i e v e d t h a t the low percentage p r o t e i n and high forage y i e l d on one hand tended to balance the high percentage p r o t e i n and low forage y i e l d on the other. Some, on t h i s b a s i s , have b e l i e v e d t h a t the p r o t e i n y i e l d s per acre of a l l pasture types are approximately equal. TABLE1 V I I I The Percentage and Y i e l d of Crude P r o t e i n (N x 6.25) by Major S o i l Zone SOIL ZONE' PROTEIN Grass Forbs T o t a l LB/A « LB/A LB/A BROWN 8.59 37.0 10.23 7.7 8.75 44.7 DARK BROWN 7.01 47.9 6.94 4.9 7.01 52.8 BLACK 6.68 59.7 6.72 85.6 SHALLOW BLACK 6.64 90.6 7.63 20.0 6.80' 110.6 GREY WOODED 6.40 22 • 2 9.77 5.3 6.86 27.5 ALLUVIUM 9.47 63.6 9.81 13.6 9.52 77.2 • In Table V I I I we f i n d a d e f i n i t e decrease i n p r o t e i n per- centage i n the forage as we go from the Brown s o i l s to the Black s o i l s . In s p i t e of t h i s , the y i e l d of p r o t e i n i n pounds per acre increases as we get i n t o the more humid zones. I t fo l l o w s then t h a t the y i e l d of other n u t r i e n t s might a l s o be greater i n the more p r o d u c t i v e s o i l s . A c o n s i d e r a t i o n of the y i e l d s of calcium and phosphorus i n Tables V and V I supports t h i s b e l i e f . The question might a r i s e : Why should so much a t t e n t i o n - 33 - be placed on p r o t e i n when r a t i n g the q u a l i t y of pasturage? The u n i v e r s a l importance of p r o t e i n has been observed f o r over a century. In f a c t , the n u t r i t i v e importance of pro- t e i n s and the dependence of animals on p l a n t s f o r these sub- stances were f i r s t pointed out by G.J. M u l d e r 1 around 1841 i n The Chemistry of Animal and Vegetable Physiology. He s a i d : " In both p l a n t s and animals a substance i s contained, which i s produced w i t h i n the former, and imparted through t h e i r food to the l a t t e r . I t i s unquestionably the most important of a l l known substances i n the organic kingdom. Without i t no l i f e appears p o s s i b l e on t h i s p l a n e t . Through i t s means the c h i e f phenomena of l i f e are produced. " A few years l a t e r , B o ussingault, w r i t i n g i n the Economie Rurale ( P a r i s , 1851) s a i d : " The alimentary v i r t u e s of p l a n t s r e s i d e above a l l i n the nitrogenous substances, and consequently t h e i r n u t r i t i v e potency i s p r o p o r t i o n a l to the q u a n t i t y of n i t r o g e n e n t e r i n g i n t o t h e i r . c o m p o s i t i o n . " In 1923, Osborne and Mendel summarized.the then current ideas on the n u t r i t i v e , values of p r o t e i n foods as f o l l o w s : " The p r o p o r t i o n of p r o t e i n i n the d i e t may determine whether l a r g e r or smaller absolute amounts of the nitrogenous f o o d s t u f f s are consumed; but the a c t u a l intake of these a l s o i s modified by the c h a r a c t e r of the non-protein i n g r e d i e n t s . The i n d i v i d u a l i n s t i n c t i v e l y s t r i v e s to s a t i s f y i t s c a l o r i f i c needs. A d i e t r i c h i n f a t s i s consumed i n smaller q u a n t i t y than one poor i n f a t s , consequently the absolute p r o t e i n i n t a k e may vary independently of i t s c o n c e n t r a t i o n or percentage i n the food. When the absolute i n t a k e i s small "the law of m i n i - mum" may come i n t o p l a y to l i m i t the e f f i c i e n c y of the whole because of the r e l a t i v e shortage of the e s s e n t i a l amino-acid ... I m p e r i a l Bureau of N u t r i t i o n . N u t r i t i o n A b s t r a c t s and reviews. 1946, 16:2 pp.10,11. \ - 34 - " Conversely, when an animal i n g e s t s a very l a r g e q u a n t i t y of some p r o t e i n poor i n an e s s e n t i a l u n i t , the absolute amount of the l a t t e r thereby a v a i l a b l e from the great abundance of i t s precursor may s u f f i c e to promote n u t r i t i v e e f f e c t s that f a i l to appear on a lower plane of p r o t e i n i n t a k e . ,f More r e c e n t l y , i t has been shown "by v a r i o u s workers (4, 17) that the q u a n t i t i e s of p r o t e i n are very c l o s e l y r e l a t e d to the q u a n t i t i e s of accessory growth f a c t o r s i n forage. I t has been pointed out, furthermore, t h a t p r o t e i n bears an i n - verse r e l a t i o n s h i p to f i b r e and l i g n i n . Thus one may imme- d i a t e l y conclude that p r o t e i n values f o r forages are good i n d i c a t o r s , not o n l y of one important n u t r i e n t , p r o t e i n , but a l s o other i n t r i n s i c c o n s t i t u e n t s which are l e s s r e a d i l y determined or defined. The assumption seems j u s t i f i e d , then, t h a t p r o t e i n i s a v e r y important fe a t u r e i n pasture q u a l i t y e s t i m a t i o n . Higher r a t e s of gain have been noted i n higher p r o t e i n pastures. Why should t h i s occur? The answer-to t h i s question perhaps does not l i e o n l y i n the r e l a t i o n s h i p of p r o t e i n t o other growth f a c t o r s but i t may.also l i e i n the narrower carbon-to-nitrogen r a t i o f o r the b a c t e r i a l f l o r a i n the d i g e s t i v e systems of the g r a z i n g animals. I f , because of the abundant supply of n i t r o g e n , b a c t e r i a l a c t i v i t y were s t i m u l a t e d , i t would appear l o g i c a l that more f i b r e or c e l l u l o s e would be broken down i n the d i g e s t i v e systems of the animals (41). Assuming that such a c o n d i t i o n favours c e l l u l o s e f e r m e n t a t i o n , i t i s suggested th a t the forage i s more completely d i g e s t e d and u t i l i z e d - 35 - because of the a c c e l e r a t e d b a c t e r i a l a c t i v i t y . Coincident with the breakdown of f i b r e , there w i l l , of course, be an increase i n b a c t e r i a l numbers. This increase should be r e - f l e c t e d i n an increase i n b a c t e r i a l p r o t e i n a v a i l a b l e to the animal. The p o s s i b l e s i g n i f i c a n c e i n b a c t e r i a l f e e d i n g of p r o t e i n has been shown by Scharrer and S t r o b e l (26). In regard to the vegetation of the Shortgrass r e g i o n , where the ground cover i s sparse but where the forage i s h i g h i n p r o t e i n , the pasturage has a h i g h q u a l i t y . In t h i s r e g i o n the " f i l l " of animals i s s m a l l e r and the d i g e s t i b i l i t y i s then increased (4). Again, w i t h the droughty c o n d i t i o n s of the r e g i o n , the feed remains i n the d i g e s t i v e systems of the animals f o r a longer p e r i o d w i t h a r e s u l t a n t increase i n the d i g e s t i b i l i t y . A c c o r d i n g l y , there might, because of these various f a c t o r s , be a higher percentage d i g e s t i b i l i t y of the forage i n the Shortgrass areas. T h i s , i n t u r n , would e x p l a i n the r e l a t i v e l y higher r a t e s of gain of l i v e s t o c k i n the region. F i n a l proof of various aspects of t h i s concept must await a d d i t i o n a l research under c o n t r o l l e d c o n d i t i o n s . I t i s seen, however, t h a t the pastures of the Brown S o i l zone are high i n q u a l i t y when based on p r o t e i n content. Pasture A p p r a i s a l i n R e l a t i o n to P r o t e i n P r o d u c t i o n Knowing t h a t : (a) An animal must have p r o t e i n , energy, m i n e r a l s , v i t a m i n s , and other f a c t o r s l e s s e a s i l y defined; - 36 - (b) carbohydrate cannot s u b s t i t u t e f o r p r o t e i n , but p r o t e i n can act as a source of energy; and, (c) the c a l o r i c values f o r p r o t e i n and carbo- hydrate are almost^ equivalent ( 4 ) , and assuming t h a t a l l forage a s s o c i a t i o n s at equal consumption r a t e s possess equal d i g e s t i b i l i t y , THEN the r a t i o of t o t a l forage y i e l d per acre to p r o t e i n y i e l d per acre on any grassland v e g e t a t i o n a l a s s o c i a t i o n should be i n d i c a t i v e of the q u a l i t y of that a s s o c i a t i o n i n terms o f a l i m i t i n g n u t r i t i o n a l c o n s t i t u e n t . ' On the assumption that 36 pounds of crude p r o t e i n i s the maintenance requirement f o r a thousand-pound cow per month (28) (the p r o t e i n of pasture herbage i s assumed to be 50 per- cent d i g e s t i b l e ( 2 4 ) ) , t h a t 7.0 percent p r o t e i n i n the pasture forage i s necessary f o r maintenance of mature animals (5) and, furthermore, that c a r r y i n g c a p a c i t y i s ra t e d on p r o t e i n y i e l d , then a pasture c o n t a i n i n g 7.0 percent p r o t e i n may be designated as a base pasture, provided that i t produces 36 pounds of p r o t e i n 1 . Now any pasture q u a l i t y r a t i o (as c a l c u l a t e d above) com- pared to the q u a l i t y r a t i o of the base pasture, should be an index of s u p e r i o r i t y o r i n f e r i o r i t y of that pasture i n terms •Brody (4) s t a t e s d a i l y p r o t e i n requirement f o r animals to be: P = 0.88 x W0-743 where P = p r o t e i n requirement ( d i g e s t i b l e ) , and W = body weight of animal i n kilograms. - 37 - of the base pasture. The index may be conveniently termed the " q u a l i t y index". Knowing the dry matter y i e l d of a g i v e n pasture and the " q u a l i t y index" of i t s v e g e t a t i o n a s s o c i a t i o n , one can e a s i l y o b t a i n a more a c c e p t i b l e r a t i n g of the c a r r y i n g c a p a c i t y by simple m u l t i p l i c a t i o n . The above statements and assumptions may be expressed in symbols as f o l l o w s : Pasture q u a l i t y r a t i o = J L P where Then we can s t a t e : where "Q" "x" "b" _ forage y i e l d i n pounds per acre _ p r o t e i n y i e l d i n pounds per acre 1 Fx Px Fb Pb 88. " q u a l i t y • index" represents any pasture represents base pasture Therefore: Q Fx Px~ x 5L Pb Fb JUL Fx Px Knowing that the pasture p r o t e i n requirement f o r mature animals i s 7.0 percent and that the t o t a l p r o t e i n require- ment per animal u n i t i s 36 pounds per month, then the gross y i e l d of the base pasture must be 36/.07 pounds per acre, or 514 pounds. (Continued next page) - 38 - Then -ZP- = M i = 14.28 trio oo Px F i n a l l y Q - * 14.28 . TABLE' IX " Q u a l i t y I n d i c e s " f o r some Grassland Types i n the Four Western Canadian Provinces S o i l Zone A s s o c i a t i o n Q u a l i t y Index . •BROWN Shortgrass p r a i r i e S a n d h i l l Sceptre p r a i r i e H a v e r h i l l p r a i r i e B.C. Lowgrass ( c u l t i v . ) B.C. Lowgrass (n a t i v e ) A l l u v i u m ( c u l t i v . ) A l l u v i u m (native) 1.5 1.4 1.3 1.4 . .8 1.3 .8 1.5 DARK BROWN ' Sask. (Cypress H i l l s ) A l b e r t a ( F o o t h i l l s ) B.C. Midgrass 1.0 1.1 .9 BLACK A l b e r t a ( F o o t h i l l s ) Sask. (Cypress H i l l s ) ' B.C. Upper grass Manitoba ( t a l l g r a s s ) Manitoba (Kentucky blue) .9 1.0 .9 .9 1.4 GREY WOODED B.C. Lower Montane .8 SHALLOW BLACK A l b e r t a ( F o o t h i l l s ) .8 The " q u a l i t y index" has been determined f o r each associa' t i o n sampled (Table I X ) , and i t i s found th a t a l l of the - 39 - a s s o c i a t i o n s i n the Dark Brown s o i l zone and the Black s o i l zone have i n d i c e s approaching 1.0. T h i s i n d i c a t e s that the c a r r y i n g c a p a c i t i e s , when r a t e d on t o t a l p r o t e i n y i e l d , are approximately the same as when rated on t o t a l dry matter y i e l d . On the other hand, the grassland types i n the Brown s o i l zone have " q u a l i t y i n d i c e s " between 1.0 and 1.5. These i n d i c e s suggest that the c a r r y i n g c a p a c i t y when c a l c u l a t e d on p r o t e i n i s g r e a t e r than the forage y i e l d c a r r y i n g c a p a c i t y . Thus, i f pasture q u a l i t y depends on p r o t e i n p r o d u c t i o n , the pastures i n the Brown s o i l zone should be r a t e d a higher c a r r y i n g c a p a c i t y than when r a t e d on forage y i e l d o n l y . The suggestion t h a t the grasslands of the Brown zone should be g i v e n a higher r a t i n g i s borne out i n l i v e s t o c k production. .It i s w e l l known tha t the o r d i n a r y c a r r y i n g c a p a c i t y estimates, f o r the sparse, short grass based on density and dry matter y i e l d s alone do not r e l a t e a c c u r a t e l y to a c t u a l numbers of l i v e s t o c k c a r r i e d and are almost always too low. A c c o r d i n g l y , the use of these " q u a l i t y i n d i c e s " f o r the a s s o c i a t i o n s i s proposed i n order t h a t more a c c e p t i b l e estimates of c a r r y i n g c a p a c i t y can be made. - 40 - ABSTRACT An i n t r o d u c t o r y i n v e s t i g a t i o n of the q u a l i t y of range forage of some v e g e t a t i o n a l a s s o c i a t i o n s of the four Western Canadian pr o v i n c e s has been presented. Although the work reported on concerns only four n u t r i e n t s , v i z . , p r o t e i n , calcium, phosphorus and ash, trends of pasture q u a l i t y by v e g e t a t i o n a l type have boen demonstrated. The' determination!, of crude p r o t e i n alone has l e d t o i n t e r e s t i n g conclusions because, of the s i g n i f i c a n t i n t e r r e l a t i o n s h i p between p r o t e i n and other p l a n t c o n s t i t u e n t s . A general p i c t u r e of vege- t a t i o n a l q u a l i t y has been p a i n t e d . As a r e s u l t of t h i s work a method of assessing the grasslands f o r q u a l i t y i s proposed wherein the r e l a t i v e pasture values are expressed as " q u a l i t y i n d i c e s " . P r o t e i n , deemed the l i m i t i n g f a c t o r i n c a r r y i n g c a p a c i t y , i s assumed to be the most important s i n g l e c r i t e r i o n f o r forage q u a l i t y e s t i m a t i o n . » - 41 - BIBLIOGRAPHY 1. A r c h i b a l d , J.G. COMPOSITION AND PALATABILITY OF SOME COMMON GRASSES. J.Ag.Res.66:341-7. May 1, 1943. 2. Ashby, E. THE QUANTITATIVE ANALYSIS OF VEGETATION. (Appendix by W.L. Stevens) Ann. Botany, .44:779-802. 1935. 3. ' A s s o c i a t i o n of O f f i c i a l A g r i c u l t u r a l Chemists. OFFICIAL AND TENTATIVE METHODS OF ANALYSIS. S i x t h E d i t i o n . 1945. .4. Brody, Samuel. BIOENERGETICS AND GROWTH. Reinhold Pub. Corp., New York. 1945. 5. ' Campbell, R.S. DETERMINATION OF GRAZING VALUES OF NATIVE VEGETATION ON SOUTHERN PINE FOREST RANGES. 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